It’s been quite some time since Twitter updated its iOS and Android apps — but now the wait is over. Twitter announced today a number of new features that appear in the micro-blogging platform’s most popular mobile versions.

The first and most significant update is a new “Activity” stream that appears under the Discover tab. According to Twitter’s description, “Activity is a stream of updates that shows which Tweets are favorited or retweeted by the people you follow and which accounts those people follow or add to lists.” Activity allows users to “tap any story once to see Tweets about a particular trend or news article,” writes Twitter on its blog. “You can then read the entire story or join the conversation by replying, retweeting or favoriting related Tweets.”

In addition to Activity, Twitter has updated the search feature, which now offers alternative spellings for search terms. Twitter says that it is now “faster” to find other users under the Connect tab. As Twitter describes it, “you can start typing the first or last name or username of the person you’re looking for and the name will autocomplete for people that you follow.”

The iPhone version of the app also includes an update to the Discover section that shows recent search queries. User profiles are also more easily accessible under the Connect tab in the iPhone version.

Finally, Twitter has added push notifications for all “interactions,” which means you will not only get a notification when someone mentions you, or retweets one of your tweets (as it was in past versions), but also receive a notification when someone follows you.

Unfortunately, the one thing Twitter really needs to update is not in this new version: revamped retweet functionality. For some insane reason, Twitter only allows users to either post straight retweets (meaning you cannot edit the tweet at all), or to “Quote Tweet,” which does allow editing, but puts quotation marks around the original tweet.

Here’s the thing: nobody* uses Quote Tweet. It is not part of the Twitter language, as much as Twitter seems to want it to be. And if you use Twitter often, it’s one of the most frustrating parts of either the mobile or Web versions. The company apparently realized the problem with Quote Tweet, as they recently updated the TweetDeck client to have an “Edit & RT” option instead of the Quote Tweet option. Fine. But what would be really great is if Twitter added his update to the iPhone and Android versions, as well as the Web version. Why they haven’t already done this is beyond me.

*Update: Ok, so apparently some people do use Quote Tweet. And some are even quite passionate about the feature. I admit that my annoyance got the better of me, and I stooped to hyperbole. My apologies. My point, however, stands: Edit & RT is, in my cranky opinion, a far superior way to retweet than Quote Tweet is. I would be absolutely giddy if Twitter updated all of its properties to include Edit & RT, and took Quote Tweet out in the back and shot it.